Incorporated in 1885, the City of Idaho Springs is located along the I-70 corridor, 18 miles west of Denver at 8,000 ft elevation. It is a popular tourist stop along the way to many ski destinations and resorts in the Colorado Rockies. The City is located in Clear Creek County that has a population of 10,000. The water utility serves approximately 2,200 people with 1,000 service connections in addition to a large number of tourists. The water supply originates from two locations: Devils Canyon (an infiltration gallery) and the Idaho Springs Reservoir via Chicago Creek with a diversion at Mattie Dam. Both supplies are situated at elevations above the water treatment plant. The reservoir is located 9 miles from the water treatment plant (WTP) and feeds Chicago Creek that runs adjacent to the WTP. Mattie Dam is a smaller dam from the early mining period of the area and is located approximately 1/4 mile adjacent to the WTP and retains the overflow from the Idaho Springs reservoir. The backwash waste generated from the new WTP is permitted to discharge directly into the Chicago Creek downstream of the intakes. In October 2001, the City underwent a period of poor raw water quality that its late 1960's conventional water plant could not produce acceptable finished water turbidity. As a result, the Colorado Department of Public Health and Environment (CDPHE) imposed a boil water order on the City. Prior to this incident, the City had been planning to upgrade its conventional plant and had estimated $7 million in plant improvements to be implemented in phases. Following the boil order, CDPHE indicated that it would not approve a phased approach and essentially required the immediate installation of a reliable filtration system. The City and its consultants elected to satisfy this requirement with the installation of a microfiltration system. The City made its decision based on good performance and reliability record of microfiltration systems operating on similar water quality sources. In addition, the City interpreted this mandate to have an improved filtration system functional by May 2002 to ensure compliance was achieved prior to the annual spring runoff period. To meet the start-up date of May 2002 the City adopted an extremely aggressive design and construction schedule. Includes table, figure, appendix.